The invention relates to a child resistant closure for containers, in particular, bottles and which is suitable for application with capping equipment.
A child resistant closure has been proposed in DE-PS No. 25 50 538, which is provided with a clutch having projections which cause interengagement of an inner cap and the outer cap during screwing on of the cap. However, during unscrewing, an axial force has to be exerted on the outer cap in the direction of the orifice, so that the projections mounted on one cap take along the projections of the other cap. Otherwise, the projections slide without unscrewing the inner cap.
Normally closures are to be screwed onto the orifices of bottles by means of automatic capping machines. The maximum torque to be exerted by the capping machine must be adjusted to a narrow tolerance, so that the bottle orifices are tightly closed, on the one hand, but that it is not closed too tightly because the inner cap would be too hard to release even by adults or perhaps be destroyed during the screwing on process.
In known child resistant closures, a child-resistant position is obtained only when the inner cap has been screwed onto the orifice with a sufficiently large torque. However, if the cap was screwed on lightly or only partially along its rotating path, it can be unscrewed without exerting an axial force in the direction of the orifice, since the clutch elements will transmit sufficient torque.